Peyton DiSiena, a sophomore biological sciences major at Cornell University, investigated nanobody binding affinities to improve cancer immunotherapy.
Chimeric antigen receptor (CAR) T cell therapy is a revolutionary new treatment for cancers, which genetically engineers a patient’s T cells to target cancer cell antigens. While effective in blood cancers, particularly lymphomas, CAR T cell therapy is not as successful in solid tumors due to the heterogeneity of antigens expressed by cancer cells. Being a part of the Broad Summer Research Program has been an unforgettable opportunity. I’ve watched myself and my peers grow so much as scientists, leaders, and individuals, embodying what will become the future of research. Though starting off this program with a limited understanding of the field of cancer biology and immunology, through hands-on research, as well as communicating with researchers and professional scientists in this field, I have gained an immense appreciation for what has been done (and what will continue to be done) within this area. The growth made over nine weeks is incredible and inspiring, and being able to do so with a cohort-become-family is a truly amazing gift.Targeting solid tumors requires generation of new CARs that recognize additional antigens. Our goal was to characterize the efficacy of single domain antibodies (nanobodies) in a solid tumor model using a cell-based assay. Nanobody CARs were transduced into Jurkat human T cells followed by co-culture with cancer cells to find which nanobodies bind most effectively to the antigen. To determine whether nanobody binding affinity impacts CAR T cell activation, we generated CAR plasmids to create a set of nanobodies with a previously defined binding affinity range to assess changes in T cell activation. CAR activation of T cell signaling was analyzed in Jurkat cells by examining upregulation of CD69 by flow cytometry. We found that the negative control and low affinity nanobodies had very low T cell activation in both the control and co-culture groups. However, higher affinity nanobody CARs displayed high levels of T cell activation in the co-culture group compared to the control. By plotting the relationship between nanobody binding affinity and T cell activation, we hypothesize that there may be a particular affinity threshold above which nanobody binding can cause high degrees of T cell activation in a cancer cell model. The results of this research might enable the application of CAR T cell immunotherapy in cancers having few treatment options, such as pancreatic and ovarian cancers.
Project: Investigating nanobody-based chimeric antigen receptors to improve cancer immunotherapy in solid tumors
Mentor: Dr. Nelson Knudsen, Ph.D., Manguso Lab & Tumor Immunotherapy Discovery Engine (TIDE)